Individual computers (commonly referred to as nodes) may be electronically connected together into a cluster to form a unified, powerful computing network. One node (commonly referred to as a master node) is selected to coordinate the activities of the non-master, or slave, nodes in the network. A master node typically initiates actions and controls decision making of non-master nodes in a network. The master node also tasks non-master nodes. A master node may malfunction, or a node may be added to a network that is more suited to be the master node than the designated master node. Therefore, there is a need for a method of establishing and updating a master node in a computer network.
U.S. Pat. No. 5,461,608, entitled “RING NETWORK WITH TEMPORARY MASTER NODE FOR COLLECTING DATA FROM SLAVE NODES DURING FAILURE,” discloses a device for and method of a slave node acting as a temporary master node if it does not receive a command message from the permanent master node. The permanent master node is assigned priority zero, whereas the slave nodes are assigned values one to four. If a slave node does not receive a command message from the permanent master node then it acts as a master node by assigning values one to four to nodes it considers slave nodes and sending out command messages to supposed slave nodes. The temporary node repeats this process until it receives a response from a node with a higher priority. The present invention does not allow slave nodes to assign priority values to other nodes, and does not allow slave nodes to send command messages as does U.S. Pat. No. 5,461,608. U.S. Pat. No. 5,461,608 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 6,950,855, entitled “MASTER NODE SELECTION IN CLUSTERED NODE CONFIGURATION,” discloses a device for and method of selecting a primary master node and a secondary master node (i.e., a master node pair) from an optimal combination of node pairs, where the optimal combination is found by searching for the maximum total availability potential of the network. The availability potential is a sum of participation indexes of a node pair minus a hamming distance between the node pair, where the hamming distance is the number of node groups the node pair do not share in common. If a master node pair does not exist in a node group then a master node is selected. The present invention does not calculate a hamming distance, sum participation indices to arrive at an availability potential, or determine an optimal combination from the availability potential as does U.S. Pat. No. 6,950,855. U.S. Pat. No. 6,950,855 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 7,269,648, entitled “RESOLVING MULTIPLE MASTER NODE CONFLICTS IN A DDB,” discloses a device for and method of selecting a master node by a global administrator. If the security of the global administrator is breached then other users may select master nodes. If there is a conflict between master nodes then the most recently selected master node is selected as the master node. The present invention does not require a global administrator, does not allow others to select global nodes if the security of a global administrator is breached, and does not resolve conflicts between master nodes by selecting the most recently selected master node as does U.S. Pat. No. 7,269,648. U.S. Pat. No. 7,269,648 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. Appl. No. 20050125501, entitled “METHOD AND APPARATUS FOR SETTING MASTER NODE OF RING NETWORK,” discloses a device for and method of setting a master node of a ring network, having adjacently connected nodes situated on rightward and leftward lines of a bi-directional transmission channel. The master node selected is one that has a number of interposed nodes counted from the leftward line that is either equal to or one less the number of interposed nodes counted from the rightward line. The present invention does not count the number of interposed nodes from either a leftward line or a rightward line and does not use such a result to choose a master node as does U.S. Pat. Appl. No. 20050125501. U.S. Pat. Appl. No. 20050125501 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. Appl. No. 20070101016, entitled “METHOD FOR CONFIRMING IDENTITY OF A MASTER NODE SELECTED TO CONTROL I/O FABRIC CONFIGURATION IN A MULTI-HOST ENVIRONMENT,” discloses a method of determining the root, or master node, when it is in doubt. The method is to compare the identification fields of the two nodes in question and determining that the master node is the one with the higher number in its identification field. The present invention does not compare the identification fields of two nodes in question to determine that the master node is the one with the higher number in its identification field as does U.S. Pat. Appl. No. 20070101016. U.S. Pat. Appl. No. 20070101016 is hereby incorporated by reference into the specification of the present invention.